Fluid Pressure Actuator

ABSTRACT

A method and apparatus including a fluid pressure actuator that includes a diaphragm that has a top and a bottom surface. In an exemplary embodiment, the fluid pressure actuator also has plunger coupled to the diaphragm and that extends from the bottom surface of the diaphragm in a first direction. The fluid pressure actuator also includes a bellow sensor that is coupled to the bottom surface of the diaphragm and that has an interior surface. In an exemplary embodiment, a height of the interior surface of the bellow sensor prevents the movement of the plunger in the first direction.

TECHNICAL FIELD

The present disclosure relates generally to a pressure actuator and, more specifically, to a fluid pressure actuator.

BACKGROUND

Subterranean systems often rely on the remote actuation of subterranean tools. For example, when a perforation system is located downhole in a well, the perforating gun is generally actuated remotely using a pressure actuator or pressure sensor that deflects or moves in response to an increase in localized pressure. The movement of the pressure actuator causes the perforating gun to fire. However, the deflection or movement of the pressure actuator may progress past an elastic deformation point and result in plastic deformation of the pressure actuator. Once this occurs, the pressure actuator may prematurely fire the perforating gun during subsequent deployments of the perforation system. The plastic deformation may also result in fatigue in the pressure actuator and a short life cycle.

The present disclosure is directed to a fluid pressure actuator and methods that overcome one or more of the shortcomings in the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the disclosure. In the drawings, like reference numbers may indicate identical or functionally similar elements.

FIG. 1 is a schematic illustration of an offshore oil and gas platform operably coupled to a perforation system including a fluid pressure actuator, according to an embodiment of the present disclosure;

FIG. 2 illustrates an isometric view of the fluid pressure actuator of FIG. 1, according to an exemplary embodiment of the present disclosure;

FIG. 3 illustrates an isometric view of a section of the fluid pressure actuator of FIG. 1, according to an exemplary embodiment of the present disclosure;

FIG. 4 illustrates a section view of a portion of the fluid pressure actuator of FIG. 1, according to an exemplary embodiment of the present disclosure;

FIG. 5 illustrates an isometric view of another portion of the fluid pressure actuator of FIG. 1, according to an exemplary embodiment of the present disclosure;

FIG. 6 illustrates a section view of the fluid pressure actuator and a portion of the perforation system of FIG. 1, according to another exemplary embodiment of the present disclosure;

FIG. 7 is a flow chart illustration of a method of operation of the fluid pressure actuator of FIG. 1, according to an exemplary embodiment of the present disclosure;

FIG. 8 illustrates a isometric view of another section of the fluid pressure actuator of FIG. 1 during a step of the method of FIG. 7, according to an exemplary embodiment of the present disclosure; and

FIG. 9 illustrates a section view of the another exemplary embodiment of the fluid pressure actuator and a portion of the perforation system of FIG. 1, according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

Illustrative embodiments and related methods of the present disclosure are described below as they might be employed in a fluid pressure actuator and method of operating the same. In the interest of clarity, not all features of an actual implementation or method are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. Further aspects and advantages of the various embodiments and related methods of the disclosure will become apparent from consideration of the following description and drawings.

The foregoing disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” “uphole,” “downhole,” “upstream,” “downstream,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the apparatus in use or operation in addition to the orientation depicted in the figures. For example, if the apparatus in the figures is turned over, elements described as being “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” may encompass both an orientation of above and below. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

Referring initially to FIG. 1, an oil or gas platform 10 is schematically illustrated. In cases where platform 10 is offshore, such as shown in FIG. 1, the offshore platform 10 may generally include a semi-submersible platform 15 is positioned over a submerged oil and gas formation 20 located below a sea floor 25. A subsea conduit 30 extends from a deck 35 of the platform 15 to a subsea wellhead installation 40, including blowout preventers 45. The platform 15 has a hoisting apparatus 50, a derrick 55, a travel block 60, a hook 65, and a swivel 70 for raising and lowering pipe strings, such as a substantially tubular, axially extending tubing string or work string 75. A wellbore 80 extends through the various earth strata including the formation 20 and may have a casing string 85 cemented therein. Disposed in a substantially vertical portion of the wellbore 80 is a perforation system 90 that includes at least one fluid pressure actuator 95. However, the fluid pressure actuator 95 may be disposed or form a part of any number of downhole systems and is not limited to the perforation system 90.

Even though FIG. 1 depicts a vertical wellbore, it should be understood by those skilled in the art that the apparatus according to the present disclosure is equally well suited for use in wellbores having other orientations including horizontal wellbores, slanted wellbores, multilateral wellbores or the like. Accordingly, it should be understood by those skilled in the art that the use of directional terms such as “above,” “below,” “upper,” “lower,” “upward,” “downward,” “uphole,” “downhole” and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure, the uphole direction being toward the surface of the well, the downhole direction being toward the toe of the well. Also, even though FIG. 1 depicts an offshore operation, it should be understood by those skilled in the art that the apparatus according to the present disclosure is equally well suited for use in onshore operations. Further, even though FIG. 1 depicts a cased hole completion, it should be understood by those skilled in the art that the apparatus according to the present disclosure is equally well suited for use in open hole completions.

FIGS. 2-4 illustrate the fluid pressure actuator 95 according to an exemplary embodiment. In one or more exemplary embodiments, the fluid pressure actuator 95 includes a diaphragm or plate 100 and a plunger 105 extending from the plate 100 in the direction indicated by the numeral 110 (“the direction 110”) illustrated in FIGS. 3, 4, 5, 6, 8, and 9. In one or more exemplary embodiments, the actuator 95 may also include a bellow sensor 115 that also extends from the plate 100 in the direction 110. In an exemplary embodiment, the plate 100 may be a circular plate having a top surface 120 and a circumferential surface 125 that defines a diameter of the plate 100. In an exemplary embodiment, a portion of the top surface 120 may slant towards the circumferential surface 125 such that a cross section view of the top surface 120 has a truncated cone shape. In other exemplary embodiments, the top surface 120 may be flat, dome shaped or convex shaped, triangular shaped, etc. In an exemplary embodiment and as shown in FIG. 4, the plate 100 also includes a bottom surface 130. In an exemplary embodiment, a protrusion 135 may be located on the bottom surface 130 or form a portion of the bottom surface 130. In one or more exemplary embodiments, the protrusion 135 is a circumferentially extending protrusion that is proximate the circumferential surface 125.

In an exemplary embodiment, the plunger 105 is a cylindrical member having an exterior surface 140. In an exemplary embodiment, the plunger 105 has a height measured along the direction 110. In an exemplary embodiment, the plate 100 and the plunger 105 are integrally formed, that is, are one piece. However, in other embodiments, the plate 100 and the plunger 105 are not integrally formed and may be coupled together in a variety of ways, such as for example, using a pin and bolt system, welds, threaded engagements, etc. Additionally, and in one or more exemplary embodiments, the plate 100 and the plunger 105 have a surface to surface frictional contact interaction.

In an exemplary embodiment, the bellow sensor 115 has an interior surface 145 and an exterior surface 150. In one or more exemplary embodiments, the interior surface 145 is concentrically disposed about the exterior surface 140 of the plunger 105. In one or more exemplary embodiments, the bellow sensor 115 includes a plurality of plates 155 that includes plates 155 a, 155 b, and 155 c. While three plates are shown, the bellow sensor 115 may include any number of plates. In one or more exemplary embodiments, each of the plates within the plurality of plates 155 may be a disc, a cylinder, a ring, or other annular or circular body. In one or more exemplary embodiments, the bellow sensor 115 has a height 156 measured along the direction 110. In one or more exemplary embodiments, the height 156 of the bellow sensor 115 is less than the height of the plunger 105.

FIG. 5 illustrates the plate 155 a according to an exemplary embodiment. In an exemplary embodiment, the plate 155 a has an interior surface that forms the interior surface 145 of the bellow sensor 115 and an exterior surface that forms the exterior surface 150 of the bellow sensor 115. In an exemplary embodiment, the plate 155 a has top surface 170 and an opposing bottom surface 175. In one or more exemplary embodiments, the plate 155 a has a circumferentially extending cavity 180 that is formed through the exterior surface 150 and towards the interior surface 145. In one or more exemplary embodiments, the cavity 180 divides the plate into a top portion 155 aa and a bottom portion 155 ab. In one or more exemplary embodiments, a circumferentially extending protrusion 185 is located on or forms a portion of the top surface 170 of the plate 155 a. In one or more exemplary embodiments, a circumferentially extending protrusion 195 is located on or forms a portion of the bottom surface 175 of the plate 155 a. In one or more exemplary embodiments, the plate 155 a is an integrally formed plate. That is, each plate from the plurality of plates 155 is a homogenous and seamless plate. In one or more exemplary embodiments, the plate 155 a has a height 205. In one or more exemplary embodiments, the top portion 155 aa has a height 210, the protrusion 185 has a height 215, the cavity 180 has a height 220, the bottom portion 155 ab has a height 225, and the protrusion 195 has a height 230. In one or more exemplary embodiments, the cavity 180 may be spaced from the interior surface 145 by a distance 235. In an exemplary embodiment, the plate 155 a has a height 236 measured in the direction 110 along the interior surface that forms the interior surface 145 of the bellow sensor 115.

In an exemplary embodiment, each of the plates 155 b and 155 c is substantially identical to the plate 155 a therefore each of the plates 155 b and 155 c will not be described in further detail. Reference numerals used to refer to the features of the plate 155 a that are substantially identical to the features of the each of the plates 155 b and 155 c will correspond to the reference numerals used to refer to the features of the plate 155 a, except that the prefix for the reference numerals used to refer to the features of the plate 155 a, that is, 155 a, will be replaced by the prefix of the each of the plates 155 b and 155 c.

In one or more exemplary embodiments, the protrusion 185 of the plate 155 a is coupled to the protrusion 135 of the diaphragm plate 100. In one or more exemplary embodiments, the protrusion 195 of the plate 155 a is coupled to the protrusion 185 of the plate 155 b and the protrusion 195 of the plate 155 b is coupled to the protrusion 185 of the plate 155 c. In one or more exemplary embodiments, coupling may include welding, soldering, brazing, or any other suitable method.

In an exemplary embodiment, and as illustrated in FIG. 6, the fluid pressure actuator 95 may be accommodated within a chamber 245 that is formed within the working string 75, such as within the perforation system 90. In one or more exemplary embodiments, the chamber 245 is circular and is formed by a wall 245 a and a floor 245 b. In an exemplary embodiment, the chamber 245 is proximate a cavity 250 in which an actuator or trigger 255 is disposed. In one or more exemplary embodiments, a passage 260 extends through the floor 245 b of the chamber 245 and to the cavity 250. In one or more exemplary embodiments, the passage 260 is sized to accommodate a portion of the plunger 105. In an exemplary embodiment, the chamber 245 has an opening 265 that receives pressurized fluid. In an exemplary embodiment, the pressurized fluid is a fluid pressurized to the wellbore hydrostatic pressure. In an exemplary embodiment, the fluid pressure actuator 95 is disposed within the chamber 245 such that the plunger 105 at least partially extends within the passage 260. In an exemplary embodiment, the protrusion 195 of the plate 155 c is coupled to a top surface of a washer 270. In an exemplary embodiment, the diameter of the washer 270 is greater than the diameter of the bellow sensor 115 and may be in contact with the wall 245 a of the chamber 245. In an exemplary embodiment, the washer 270 may be sized such that the washer 270 is secured against or proximate the floor 245 b of the chamber 245 using a friction fit, snap fit, etc. In an exemplary embodiment, the washer forms a first channel 275 and a second channel 280. In an exemplary embodiment, a first elastomeric seal 285 is accommodated within the first channel 275. In an exemplary embodiment, a second elastomeric seal 290 is accommodated within the second channel 280. In one or more exemplary embodiments, the elastomeric seals 285 and 290 may be an o-ring or other similar device. In an exemplary embodiment, the plate 155 c may be coupled to the washer 270 using a weld, corresponding threaded connections, or any other suitable fastener.

In an exemplary embodiment and as illustrated in FIG. 7 with continuing reference to FIGS. 2-5, a method 300 of operating the fluid pressure actuator 95 includes sizing the fluid pressure actuator 95 at step 305; accommodating the fluid pressure actuator 95 within the chamber 245 at step 310; accommodating a portion of the plunger 105 within the passage 260 at step 315; allowing the pressurized fluid to enter the chamber 245 at step 320; moving the plate 100 in the direction 110 at step 325; and moving the plunger 105 in the direction 110 to activate a system controlled by the trigger 255 at step 330.

More specifically, at the step 305, the fluid pressure actuator 95 is sized. That is, any one or more of the height 205 of each of the plates 155 a, 155 b, and 155 c; and the height 210 of the top portion 155 aa, 155 ba, and 155 ca; the height 215 of each of the protrusions 185; the height 220 of each of the cavities 180; the height 225 of each of the bottom portions 155 ba, 155 bb, and 155 cb; the height 230 of each of the protrusions 195; the distance 235 associated with each of the plates 155 a, 155 b, and 155 c; and the height 236 of the plates 155 a, 155 b, and 155 c or any combination thereof, may be sized based on any one or more of the pressure rating design, the type of the trigger 255, the working string 75, etc. In an exemplary embodiment, the fluid pressure actuator 95 may be sized based on the pressure rating design, the type of the trigger 255, the working string 75, etc. In one or more exemplary embodiments, the number of plates in the plurality of plates 155 is determined based on the pressure rating design, the type of the trigger 255, the working string 75, etc. In one or more exemplary embodiments, each of the plates in the plurality of plates 155 is “stacked” or otherwise arranged such that each of the protrusions 195 of the plate 155 a and 155 b aligns with the protrusions of the plate 155 b and 155 c, respectively. In one or more exemplary embodiment, the protrusion 185 is welded to the protrusion 195 near the exterior surface 150 of the bellow sensor 115. In one or more exemplary embodiments, the protrusion 135 is coupled to the protrusion 185, such as for example, by welding the protrusion 135 to the protrusion 185 near the exterior surface 155, to form an annular chamber 350 that is at least partially defined by the bottom surface 130 of the plate 100 and the top surface 170 of the plate 155 a. In an exemplary embodiment, the stacking of the plate 155 a and the plate 155 b forms an annular chamber 355 that is at least partially defined by the bottom surface 175 of the plate 155 a and the top surface of the plate 155 b. In an exemplary embodiment, the height of the chamber 350 is dependent upon the height of the protrusion 135 and the height 215 of the protrusion 185. In an exemplary embodiment, the height of the annular chamber 355 is dependent upon the height 215 of the protrusion 185 and the height 230 of the protrusion 195. In an exemplary embodiment, the diameter of the washer 270 may be sized based on the size of the chamber 245. For example, the diameter of the washer 270 may be marginally smaller than an inner diameter formed by the wall 245 a of the chamber 245 such that the fluid pressure actuator 95 may be secured within the chamber 245 via a friction fit, snap fit, a threaded engagement, etc. In an exemplary embodiment, the diameter of the plates 155 a, 155 b, and 155 c may be sized smaller than the diameter of the washer 270 such that the exterior surface 150 of the bellow sensor 115 is spaced from the wall 245 a of chamber 245. In an exemplary embodiment, the fluid pressure actuator 95 is sized and is a function of a pressure rating design intent. In an exemplary embodiment, the height 236 is sized based on the pressure rating design intent. In an exemplary embodiment, the fluid pressure actuator comprises the bellow sensor 115 that comprises at least two u-shaped plates, each having opposing arms and forming a cavity therebetween with an outwardly extending protrusion at the end of each arm, the plates positioned adjacent one another such that the protrusion of one plate abuts the protrusion of the other plate to form a chamber between the plates; a diaphragm adjacent one of the plates; and a plunger extending from the diaphragm.

At the step 310, the fluid pressure actuator 95 is accommodated in the chamber 245 formed within the workings string 75. In one or more exemplary embodiments, the fluid pressure actuator 95 is accommodated in the chamber 245 such that the fluid pressure actuator 95 is secured within the chamber 245, such as for example, via a friction fit or snap fit between the exterior surface of the washer 270 and the wall 245 a of the chamber 245. In one or more exemplary embodiments, the fluid pressure actuator 95 is accommodated in the chamber 245 such that the first elastomeric seal 285 that is accommodated within the first channel 275 of the washer 270 fluidically isolates the passage 260 from the opening 265 of the chamber 245. In an exemplary embodiment, the fluid pressure actuator 95 is accommodated within the chamber 245 such that the second elastomeric seal 290 that is accommodated within the second channel 280 fluidically isolates the passage 260 from the opening 265 of the chamber 245.

At the step 315, the plunger 105 is accommodated within the passage 260. In one or more exemplary embodiments, when the fluid pressure actuator 95 is accommodated within the chamber 245, at least a portion of the plunger 105 extends within or through the passage 260.

At the step 320, the pressurized fluid is allowed to enter the chamber 245. In one or more exemplary embodiments, a mud or other wellbore fluid that is circulated downhole is the pressurized fluid that enters the chamber 245. However, the pressurized fluid may also be stored within a portion of the working string 75 and released to enter the chamber 245 by instruction from a surface system or upon rupture of a rupture disk or the like.

At the step 325, the plate 100 is moved in the direction 110 due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator 95 that are exposed to the pressurized fluid. For example, the top surface 120 of the plate 100 may be moved in the direction 110 at step 325. In one or more exemplary embodiments, the pressurized fluid applies a force on the top surface 120 of the plate 100 along with a force to the circumferential surface 125, the exterior surface 150 of the bellow sensor 115, and the surfaces that form the cavity 180. In one or more exemplary embodiments, the application of a force on the one or more surfaces that are exposed to the pressurized fluid causes movement of the fluid pressure actuator 95. That is, the application of the force one the one or more surfaces that are exposed to the pressurized fluid causes at least a portion of the fluid pressure actuator 95 to deform or deflect. In one or more exemplary embodiments, the plate 100 may deform or move and/or any one or more of the plates 155 a, 155 b, and 155 c may deform or move. In an exemplary embodiment, deformation or movement of the plate 100 and or any one of the plates 155 a, 155 b, and 155 c causes the plunger 105 to move in the direction 110. In an exemplary embodiment, and in response to the plunger 105 moving in the direction 110, the portion of the bellow sensor 115 near the plunger 105 is compressed. That is, the height of one or more of the chamber 350, the annular chamber 355 between the plate 155 a and 155 b, the annular chamber 355 between the plate 155 b and 155 c is shortened at a location proximate the plunger 105. In an exemplary embodiment, the height of one or more of the cavity 180 of the plate 155 a, the cavity 180 of the plate 155 b, and the cavity 180 of the plate 155 c is extended at a location proximate the exterior surface 150 to reduce the stress/strain on the exterior surface 150 of the bellow sensor 115. In an exemplary embodiment, the movement of the plate 100 in the direction 110 is a function of a height of the chamber 350, which corresponds to the height of the protrusion 135 and the height 215 of the protrusion 185 of the plate 155 a, and the height of the annular chambers 355 formed between the plate 155 a and 155 b and formed between the plate 155 b and 155 c, which corresponds to the height 230 of the protrusions 195 of the plate 155 a and the plate 155 b and the height 215 protrusions 185 of the plate 155 b and the plate 155 c.

At the step 330, the plunger 105 activates a system controlled by the trigger 255. In an exemplary embodiment, the plunger 105 moves in the direction 110 and compresses or otherwise actuates the trigger 255. In an exemplary embodiment and as illustrated in FIG. 8, and due to the height 236 of the plates 155 a, 155 b, and 155 c, the movement of the top plate 100 in the direction 110 is limited. That is, the deformation or movement of the bellow sensor 115 is limited by the plates 155 a, 155 b, and 155 c such the elastic deformation range of the bellow sensor 115 is not exceeded. The limited range of movement of the top plate 100 results in a shallower angle of deflection for the top plate 100 and the bellow sensor 115. In an exemplary embodiment, the more limited the range of movement of the top plate 100 the less stress is applied to the fluid pressure actuator 95. In an exemplary embodiment, the fluid pressure actuator 95 may be sized to allow movement of the plunger 105 in the direction 110 sufficient to actuate the trigger 255 but to reduce the amount of stress and fatigue exerted on the fluid pressure actuator 95. Additionally, the fluid pressure actuator 95 may be sized to allow movement of the plunger 105 in the direction 110 sufficient to actuate the trigger 255 but to prevent or reduce the stress exerted on the fluid pressure actuator 95 such that the stress does not exceed the elastic limit of the material of the fluid pressure actuator 95. In an exemplary embodiment, the reduction of stress exerted on the fluid pressure actuator 95 may increase the life cycle of the fluid pressure actuator 95.

In one or more exemplary embodiments, and as illustrated in FIG. 9, the washer 270 forms the top portion 155 ca.

In one or more exemplary embodiments, a method of operating the fluid pressure actuator 95 includes introducing a pressurized fluid into a pressure chamber of a downhole tool; utilizing the pressurized fluid to elastically compress a diaphragm of a pressure fluid actuator into a chamber formed between the diaphragm and a first plate; elastically compressing the first plate into a chamber formed between the first plate and a second plate; as the plates are elastically compressed, utilizing the diaphragm to urge a plunger into engagement with an actuator. In one or more exemplary embodiments, each of the first plate and the second plate is a u-shaped plate, each having opposing arms and forming a cavity therebetween with an outwardly extending protrusion at the end of each arm, the first plate and the second plate are positioned adjacent one another such that the protrusion of the first plate abuts the protrusion of the second plate to form the chamber formed between the first plate and the second plate. In one or more exemplary embodiments, the method also includes preventing the compression of the diaphragm using each of the arms. That is, the compression of the diaphragm is limited due to the diaphragm resting on the arms of the first plate and the compression of the first plate is limited due to the first plate resting on the arms of the second plate. In an exemplary embodiment, the height of the chambers limits the compression of the diaphragm and the first plate to prevent or discourage plastic deformation of the diaphragm and/or the first plate.

In an exemplary embodiment, the fluid pressure actuator 95 and/or a portion of the method 300 may be used as a reliable trigger to fire a perforating gun. In an exemplary embodiment, the actuator 95 and/or a portion of the method 300 may be used as a reliable pressure compensator. In an exemplary embodiment, the fluid pressure actuator 95 and/or a portion of the method 300 may improve surface safety. In an exemplary embodiment, the fluid pressure actuator 95 and/or a portion of the method 300 may be used in applications such as fail-safe for pressure sensing to prevent the arming until the tool is properly located downhole.

In an exemplary embodiment, one method of coupling any two of the plates 100, 155 a, 155 b, and 155 c is e.beam welding of outer intersecting surfaces (i.e., e.beam will fire its charge to fuse and bond surfaces of the protrusion 135 and the protrusion 185). In an exemplary embodiment, the fluid pressure actuator 95 may be used for or in any downhole tool and is not limited to the perforating system 90. In an exemplary embodiment, the fluid pressure actuator 95 is a linear expansion bellow device that can be deformed along the direction 110 to cause the plunger 105 to translate and trigger a certain event. In an exemplary embodiment, the plunger 105 may be linked directly or indirectly to a switch or an apparatus to trigger an event of interest. In an exemplary embodiment, the fluid pressure actuator 95 may be composed of any elastic material, such as for example, stainless steel 316. In one or more exemplary embodiment, the fluid pressure actuator 95 may be composed of a homogenous and isotropic material such that the stress fields may be similar throughout the fluid pressure actuator 95. In an exemplary embodiment, any ratios formed between the heights 205, 210, 215, 220, 225, 230, 235, and 236 are dependent upon the pressure rating design, the type of the trigger 255, the working string 75, etc. In an exemplary embodiment, the number of plates in the plurality of plates 155 is dependent upon any one of the expected pressure exerted on the fluid pressure actuator 95, the material properties of the fluid pressure actuator 95 and the amount of movement of the plunger 105 in the direction 110 to activate the actuator or trigger 255. In an exemplary embodiment, a channel (not shown) is formed in the exterior surface of the washer 270 to accommodate an elastomeric seal (not shown), such as an o-ring. In an exemplary embodiment, the elastomeric seal accommodated atop the exterior surface of the washer 270 fluidically seals the passage 260 from the opening 265 of the chamber 245.

Thus, a fluid pressure actuator has been described. Embodiments of the fluid pressure actuator may generally include a diaphragm having a top surface and a bottom surface; a plunger coupled to the diaphragm and extending away from the bottom surface of the diaphragm in a first direction; and a bellow sensor that extends away from the bottom surface of the diaphragm in the first direction, with the bellow sensor including a first circular plate coupled to the diaphragm, the first plate including an interior surface of the first plate that is concentrically disposed about an exterior surface of the plunger; an opposing exterior surface of the first plate; and a first circumferentially extending cavity extending from the exterior surface of the first plate towards the first interior surface of the first plate. Any of the foregoing embodiments may include any one of the following elements, alone or in combination with each other:

A top surface of the first plate forms a first circumferentially extending protrusion.

The first protrusion of the top surface of the first plate is coupled to the bottom surface of the diaphragm to form a first annular chamber that extends from the interior surface of the first plate towards the exterior surface of the first plate and that is at least partially defined by the bottom surface of the diaphragm and the top surface of the first plate.

The first protrusion of the top surface of the first plate is coupled to a circumferentially extending protrusion formed on the bottom surface of the diaphragm to form the first annular chamber.

The bellow sensor includes a second circular plate coupled to the first plate, the second plate also includes an interior surface of the second plate that is concentrically disposed about the exterior surface of the plunger; an opposing exterior surface of the second plate; and a second radially extending cavity extending from the exterior surface of the second plate towards the interior surface of the second plate.

A top surface of the second plate forms a second circumferentially extending protrusion.

The second protrusion of the top surface of the second plate is coupled to a bottom surface of the first plate to form a second annular chamber that extends from the second interior surface of the second plate towards the second exterior surface of the second plate and that is at least partially defined by the bottom surface of the first plate and the top surface of the second plate.

The plunger extends beyond the bellow sensor in the first direction by a first distance.

A bottom surface of the second plate forms a circular channel.

An elastomeric seal is accommodated within the circular channel.

Movement of the plunger in the first direction is based on a height of the second annular chamber that is measured along the first direction.

The interior surface of the first plate has a height measured along the first direction that is sized to limit movement of the plunger in the first direction.

Thus, a method for actuating a subterranean system has been described. Embodiments of the method generally include providing a fluid pressure actuator within a chamber that is formed within a working string, the fluid pressure actuator including: a diaphragm having a top surface and a bottom surface; a plunger coupled to the diaphragm and extending away from the bottom surface of the diaphragm in a first direction; and a bellow sensor that extends away from the bottom surface of the diaphragm in the first direction, the bellow sensor including: a first circular plate coupled to the diaphragm, the first plate including: an interior surface of the first plate that is concentrically disposed about an exterior surface of the plunger; an opposing exterior surface of the first plate; and a first circumferentially extending cavity extending from the exterior surface of the first plate towards the first interior surface of the first plate; accommodating a portion of the plunger within an opening formed in a floor of the chamber; allowing a pressurized fluid to enter the chamber; moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction; and depressing an actuator located below the floor of the chamber, using the plunger, to activate the subterranean system controlled by the actuator.

For any of the foregoing embodiments, the method may include any one of the following limitations, alone or in combination with each other:

A top surface of the second plate forms a second circumferentially extending protrusion.

The second protrusion of the top surface of the second plate is coupled to a bottom surface of the first plate to form a second annular chamber that extends from the second interior surface of the second plate towards the second exterior surface of the second plate and that is at least partially defined by the bottom surface of the first plate and the top surface of the second plate.

The plunger extends beyond the bellow sensor in the first direction by a first distance.

Accommodating an elastomeric seal within a radial channel formed within a bottom surface of the second plate to fluidically isolate the actuator from the chamber.

Sizing a height of the first protrusion along the first direction and a height of the second protrusion along the first direction to limit the movement of the plunger in the first direction.

Moving the plunger in the first direction due to the pressurized fluid applying a force against the one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction includes deforming the bellow sensor to reduce a height of the first annular chamber.

Moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction includes deforming the bellow sensor to reduce a height of the second annular chamber.

Thus, a method for actuating a downhole tool has been described. Embodiments of the method generally include introducing a pressurized fluid into a pressure chamber of the downhole tool; utilizing the pressurized fluid to elastically compress a diaphragm into a chamber formed between the diaphragm and a first plate; elastically compressing the first plate into a chamber formed between the first plate and a second plate; and utilizing the diaphragm to urge a plunger into engagement with an actuator when the plates are elastically compressed.

For any of the foregoing embodiments, the method may include any one of the following limitations, alone or in combination with each other:

Each of the first plate and the second plate is a u-shaped plate, each having opposing arms and forming a cavity therebetween with an outwardly extending protrusion at the end of each arm; and the first plate and the second plate are positioned adjacent one another such that the protrusion of the first plate abuts the protrusion of the second plate to form the chamber formed between the first plate and the second plate.

Limiting the compression of the diaphragm using the arms of the first plate.

A height of the chamber formed between the diaphragm and a first plate and a height of the chamber formed between the first plate and the second plate limits the compression of the diaphragm to discourage the plastic deformation of the diaphragm.

The foregoing description and figures are not drawn to scale, but rather are illustrated to describe various embodiments of the present disclosure in simplistic form. Although various embodiments and methods have been shown and described, the disclosure is not limited to such embodiments and methods and will be understood to include all modifications and variations as would be apparent to one skilled in the art. Therefore, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Accordingly, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims. 

What is claimed is:
 1. A fluid pressure actuator, comprising: a diaphragm having a top surface and a bottom surface; a plunger coupled to the diaphragm and extending away from the bottom surface of the diaphragm in a first direction; and a bellow sensor that extends away from the bottom surface of the diaphragm in the first direction, the bellow sensor comprising: a first plate coupled to the diaphragm, the first plate comprising: an interior surface of the first plate that is concentrically disposed about an exterior surface of the plunger; an opposing exterior surface of the first plate; and a first circumferentially extending cavity extending from the exterior surface of the first plate towards the first interior surface of the first plate.
 2. The fluid pressure actuator of claim 1, wherein a top surface of the first plate forms a first circumferentially extending protrusion; and wherein the first protrusion of the top surface of the first plate is coupled to the bottom surface of the diaphragm to form a first annular chamber that extends from the interior surface of the first plate towards the exterior surface of the first plate and that is at least partially defined by the bottom surface of the diaphragm and the top surface of the first plate.
 3. The fluid pressure actuator of claim 2, wherein the first protrusion of the top surface of the first plate is coupled to a circumferentially extending protrusion formed on the bottom surface of the diaphragm to form the first annular chamber.
 4. The fluid pressure actuator of claim 1, wherein the bellow sensor further comprises: a second circular plate coupled to the first plate, the second plate comprising: an interior surface of the second plate that is concentrically disposed about the exterior surface of the plunger; an opposing exterior surface of the second plate; and a second radially extending cavity extending from the exterior surface of the second plate towards the interior surface of the second plate.
 5. The fluid pressure actuator of claim 4, wherein a top surface of the second plate forms a second circumferentially extending protrusion; and wherein the second protrusion of the top surface of the second plate is coupled to a bottom surface of the first plate to form a second annular chamber that extends from the second interior surface of the second plate towards the second exterior surface of the second plate and that is at least partially defined by the bottom surface of the first plate and the top surface of the second plate.
 6. The fluid pressure actuator of claim 5, wherein the second protrusion of the top surface of the second plate is coupled to a third circumferentially extending protrusion formed on the bottom surface of the first plate to form the second annular chamber.
 7. The fluid pressure actuator of claim 1, wherein the plunger extends beyond the bellow sensor in the first direction by a first distance.
 8. The fluid pressure actuator of claim 4, wherein a bottom surface of the second plate forms a circular channel.
 9. The fluid pressure actuator of claim 8, further comprising an elastomeric seal accommodated within the circular channel.
 10. The fluid pressure actuator of claim 1, wherein the interior surface of the first plate has a height measured along the first direction that is sized to limit movement of the plunger in the first direction.
 11. The fluid pressure actuator of claim 5, wherein movement of the plunger in the first direction is based on a height of the second annular chamber that is measured along the first direction.
 12. A method for actuating a downhole tool, the method comprising: introducing a pressurized fluid into a pressure chamber of the downhole tool; utilizing the pressurized fluid to elastically compress a diaphragm into a chamber formed between the diaphragm and a first plate; elastically compressing the first plate into a chamber formed between the first plate and a second plate; and utilizing the diaphragm to urge a plunger into engagement with an actuator when the plates are elastically compressed.
 13. The method of claim 12, wherein each of the first plate and the second plate is a u-shaped plate, each having opposing arms and forming a cavity therebetween with an outwardly extending protrusion at the end of each arm; and wherein the first plate and the second plate are positioned adjacent one another such that the protrusion of the first plate abuts the protrusion of the second plate to form the chamber formed between the first plate and the second plate.
 14. The method of claim 13, further comprising limiting the compression of the diaphragm using the arms of the first plate.
 15. The method of claim 14, wherein a height of the chamber formed between the diaphragm and a first plate and a height of the chamber formed between the first plate and the second plate limits the compression of the diaphragm to discourage the plastic deformation of the diaphragm.
 16. A method for actuating a downhole tool, the method comprising: providing a fluid pressure actuator within a chamber that is formed within a working string, the fluid pressure actuator comprising: a diaphragm having a top surface and a bottom surface; a plunger coupled to the diaphragm and extending away from the bottom surface of the diaphragm in a first direction; and a bellow sensor that extends away from the bottom surface of the diaphragm in the first direction, the bellow sensor comprising: a first circular plate coupled to the diaphragm, the first plate comprising: an interior surface of the first plate that is concentrically disposed about an exterior surface of the plunger; an opposing exterior surface of the first plate; and a first circumferentially extending cavity extending from the exterior surface of the first plate towards the first interior surface of the first plate; accommodating a portion of the plunger within an opening formed in a floor of the chamber; allowing a pressurized fluid to enter the chamber; moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction; and depressing an actuator located below the floor of the chamber, using the plunger, to activate the subterranean system controlled by the actuator.
 17. The method of claim 16, wherein a top surface of the first plate forms a first circumferentially extending protrusion; and wherein the first protrusion of the top surface of the first plate is coupled to the bottom surface of the diaphragm to form a first annular chamber that extends from the interior surface of the first plate towards the exterior surface of the first plate and that is at least partially defined by the bottom surface of the diaphragm and the top surface of the first plate.
 18. The method of claim 17, wherein the first protrusion of the top surface of the first plate is coupled to a circumferentially extending protrusion formed on the bottom surface of the diaphragm to form the first annular chamber.
 19. The method of claim 16, wherein the bellow sensor further comprises: a second circular plate coupled to the first plate, the second plate comprising: an interior surface of the second plate that is concentrically disposed about the exterior surface of the plunger; an opposing exterior surface of the second plate; and a second radially extending cavity extending from the exterior surface of the second plate towards the interior surface of the second plate.
 20. The method of claim 19, wherein a top surface of the second plate forms a second circumferentially extending protrusion; and wherein the second protrusion of the top surface of the second plate is coupled to a bottom surface of the first plate to form a second annular chamber that extends from the second interior surface of the second plate towards the second exterior surface of the second plate and that is at least partially defined by the bottom surface of the first plate and the top surface of the second plate.
 21. The method of claim 20, wherein the second protrusion of the top surface of the second plate is coupled to a third circumferentially extending protrusion formed on the bottom surface of the first plate to form the second annular chamber
 22. The method of claim 16, wherein the plunger extends beyond the bellow sensor in the first direction by a first distance.
 23. The method of claim 19, wherein an elastomeric seal is accommodated within a radial channel formed within a bottom surface of the second plate to fluidically isolate the actuator from the chamber.
 24. The method of claim 21, further comprising sizing a height of the first protrusion along the first direction and a height of the second protrusion along the first direction to limit the movement of the plunger in the first direction.
 25. The method of claim 16, wherein moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction comprises deforming the bellow sensor to reduce a height of the first annular chamber.
 26. The method of claim 20, wherein moving the plunger in the first direction due to the pressurized fluid applying a force against one or more surfaces of the fluid pressure actuator that are exposed to the pressurized fluid in the first direction comprises deforming the bellow sensor to reduce a height of the second annular chamber. 